Time: From Earth Rotation to Atomic Physics


Book Description

This accessible reference presents the evolution of concepts of time and methods of time keeping, for historians, scientists, engineers, and educators. The second edition has been updated throughout to describe twentieth- and twenty-first-century advances, progress in devices, time and cosmology, the redefinition of SI units, and the future of UTC.




Time and the Earth’s Rotation


Book Description

IAU Symposium No. 82, "Time and the Earth's Rotation", met to discuss modern research in the field of the rotation of the Earth with particu lar emphasis on the role of new observational techniques in this work. The use of these techniques has prompted a new look at the definitions of the traditional reference systems and the concepts of the rotation of the Earth around its center of mass. Specific topics discussed were time, polar motion, reference systems, conventional radio interferometry, very'long baseline interferometry (VLBI), Doppler satellite methods, satellite laser ranging, lunar laser ranging, and geophysical research concerning the Earth's rotation. Improvement in the accuracy of the observations is a key to possible solutions of the many unsolved problems remaining in this field. It appears that such improvement, using both classical and new techniques, is forthcoming in the near future. This will surely contribute to a better understanding of some of the long-standing questions concerning the rotation of the Earth around its center of mass and lead to an improved knowledge of the rotating, deformable Earth. This volume contains the papers presented at IAU Symposium No. 82 as well as the discussions provoked by these papers. It is hoped that it captures the principal points of the meeting and that it will contribute not only to a better understanding of existing problems, but also to future research in time and the Earth's rotation.




Historical Eclipses and Earth's Rotation


Book Description

This book is intended for geophysicists, astronomers (especially those with an interest in history), historians and orientalists. The culmination of many years of research, it discusses, in depth, ancient and medieval eclipse observations and their importance in studying Earth's past rotation. This was the first major book on this subject to appear in the last twenty years. The author has specialised in the interpretation of early astronomical records and their application to problems in modern astronomy for many years. The book contains an in-depth discussion of numerous eclipse records from Babylon, China, Europe and the Arab lands. Translations of almost every record studied are given. It is shown that although tides play a dominant long-term role in producing variations in Earth's rate of rotation - causing a gradual increase in the length of the day - there are significant, and variable non-tidal changes in opposition to the main trend.




The Age of Miracles


Book Description

NAMED ONE OF THE BEST BOOKS OF THE YEAR BY People ∙ O: The Oprah Magazine ∙ Financial Times ∙ Kansas City Star ∙ BookPage ∙ Kirkus Reviews ∙ Publishers Weekly ∙ Booklist NEW YORK TIMES BESTSELLER “A stunner.”—Justin Cronin “It’s never the disasters you see coming that finally come to pass—it’s the ones you don’t expect at all,” says Julia, in this spellbinding novel of catastrophe and survival by a superb new writer. Luminous, suspenseful, unforgettable, The Age of Miracles tells the haunting and beautiful story of Julia and her family as they struggle to live in a time of extraordinary change. On an ordinary Saturday in a California suburb, Julia awakes to discover that something has happened to the rotation of the earth. The days and nights are growing longer and longer; gravity is affected; the birds, the tides, human behavior, and cosmic rhythms are thrown into disarray. In a world that seems filled with danger and loss, Julia also must face surprising developments in herself, and in her personal world—divisions widening between her parents, strange behavior by her friends, the pain and vulnerability of first love, a growing sense of isolation, and a surprising, rebellious new strength. With crystalline prose and the indelible magic of a born storyteller, Karen Thompson Walker gives us a breathtaking portrait of people finding ways to go on in an ever-evolving world. “Gripping drama . . . flawlessly written; it could be the most assured debut by an American writer since Jennifer Egan’s Emerald City.”—The Denver Post “Pure magnificence.”—Nathan Englander “Provides solace with its wisdom, compassion, and elegance.”—Curtis Sittenfeld “Riveting, heartbreaking, profoundly moving.”—Kirkus Reviews (starred review) Look for special features inside. Join the Circle for author chats and more.




Time and the Earth’s Rotation


Book Description

IAU Symposium No. 82, "Time and the Earth's Rotation", met to discuss modern research in the field of the rotation of the Earth with particu lar emphasis on the role of new observational techniques in this work. The use of these techniques has prompted a new look at the definitions of the traditional reference systems and the concepts of the rotation of the Earth around its center of mass. Specific topics discussed were time, polar motion, reference systems, conventional radio interferometry, very'long baseline interferometry (VLBI), Doppler satellite methods, satellite laser ranging, lunar laser ranging, and geophysical research concerning the Earth's rotation. Improvement in the accuracy of the observations is a key to possible solutions of the many unsolved problems remaining in this field. It appears that such improvement, using both classical and new techniques, is forthcoming in the near future. This will surely contribute to a better understanding of some of the long-standing questions concerning the rotation of the Earth around its center of mass and lead to an improved knowledge of the rotating, deformable Earth. This volume contains the papers presented at IAU Symposium No. 82 as well as the discussions provoked by these papers. It is hoped that it captures the principal points of the meeting and that it will contribute not only to a better understanding of existing problems, but also to future research in time and the Earth's rotation.




The Earth's Variable Rotation


Book Description

An analysis of the irregular rotation of the Earth and the geophysical mechanisms responsible for it.










Relating Time to the Earth's Variable Rotation


Book Description

With the beginning of the 21st Century, the timing community finds itself again facing a decades-old problem of how to synchronize a uniform time scale with time derived from the Earth's rotation. Atomic time is the basis for most everyday timing applications, However, time astronomically determined from the Earth's rotation is essential for other applications including navigation. The history of relating atomic time to the Earth's rotation is presented, including background information related to the current synchronization method of leap seconds.




Encyclopedia of the Solar System


Book Description

Long before Galileo published his discoveries about Jupiter, lunar craters, and the Milky Way in the Starry Messenger in 1610, people were fascinated with the planets and stars around them. That interest continues today, and scientists are making new discoveries at an astounding rate. Ancient lake beds on Mars, robotic spacecraft missions, and new definitions of planets now dominate the news. How can you take it all in? Start with the new Encyclopedia of the Solar System, Second Edition. This self-contained reference follows the trail blazed by the bestselling first edition. It provides a framework for understanding the origin and evolution of the solar system, historical discoveries, and details about planetary bodies and how they interact—and has jumped light years ahead in terms of new information and visual impact. Offering more than 50% new material, the Encyclopedia includes the latest explorations and observations, hundreds of new color digital images and illustrations, and more than 1,000 pages. It stands alone as the definitive work in this field, and will serve as a modern messenger of scientific discovery and provide a look into the future of our solar system. · Forty-seven chapters from 75+ eminent authors review fundamental topics as well as new models, theories, and discussions · Each entry is detailed and scientifically rigorous, yet accessible to undergraduate students and amateur astronomers · More than 700 full-color digital images and diagrams from current space missions and observatories amplify the chapters · Thematic chapters provide up-to-date coverage, including a discussion on the new International Astronomical Union (IAU) vote on the definition of a planet · Information is easily accessible with numerous cross-references and a full glossary and index